铜对水生生物的毒性:类群特异性敏感度分析

铜的毒性因受多种环境因素(如温度、pH等)的影响,其水质基准和标准经历过多次修改。由于不同区系生物受生活环境等因素的影响,不同物种对铜的耐受性和敏感度上存在很大的差异。本文通过构建类群特异性敏感度分布,以及对10%安全浓度值(10%hazardous concentration,HC_(10))及其95%置信区间(95%confidence interval,95%CI)的比较,分析了铜对淡水和海水各类群的敏感度差异,以期为我国在制定相关水质基准的物种选择上提供参考。结果显示,淡水系统中藻类为对铜毒性最敏感类群,其次为甲壳类,软体动物类,鱼类,寡毛类,而昆虫类为对铜的最耐受类群。海水各类群对铜的敏感度顺序与淡水类似,只是在寡毛类和鱼类顺序上有所不同。相对于海洋物种,淡水水体生物总体上比海水中各相应类群生物对铜更为敏感。

Taxon-specific Sensitivity Differences of Copper to Aquatic Organisms

The toxicity of copper is affected by many environmental factors, e.g. temperature, pH, etc. To better control copper's discharge and protect aquatic organisms from the toxicity of copper, the water quality criteria (WQC) of copper have been updated several times so as to reflect the latest scientific knowledge. To date, the differences of species' tolerance and sensitivities to copper might exist partly due to the effects of environmental factor on different taxon living in different geographical regions. Using all available fresh water and marine toxicity data in the literature, taxon-specific species sensitivities were compared by using species sensitivity distributions (SSDs) approach. The results obtained in the present study can provide a reference for species selection of WQC development in China. Through a comprehensive meta-analysis of taxon-specific 10% hazardous concentrations (HC₁₀) and their 95% confidence interval (95% CI), our results suggest that algae is the most sensitive taxa to copper in fresh water ecosystems, followed by crustaceans, molluscs, fishes and worms, while insects is the least sensitive one. Comparatively, there is almost a similar decline in copper sensitivity from algae to crustaceans, molluscs, worms and then fishes for marine organism. Whereas, fresh water taxa is more sensitive against copper than their marine counterparts.